Immediate incorporated hip spica casting in pediatric femoral fractures: comparison of efficacy between normal and high-risk groups.

Background: Immediate hip spica casting is the most commonly used method for the treatment of pediatric femoral fractures. The main disadvantage of the method is the unacceptable shortening (>25 mm), which may occur during the treatment. Buehler et al described the so-called telescope test to identify the cases with a relatively high risk of unacceptable shortening. On the basis of this test, patients with an overriding of the fracture ends of more than 30 mm have a 20.4 times higher risk of unacceptable shortening compared with those with an overriding of less than 30 mm. This relatively higher risk of unacceptable shortening may be avoided by a hip spica cast, which is incorporated to a distal femoral traction pin.

Methods: The study consists of 47 (26 boys and 21 girls) patients. Mean age was 40.3 months (range, 18 months to 6 years). Patients were divided into 2 groups according to the telescope test. Group 1 included patients with telescope test results of more than 30 mm. Group 2 included patients with telescope test results of 30 mm or less. All patients were treated with a hip spica cast, which is incorporated to a distal femoral traction pin within 8 hours of the initial trauma. During cast treatment, patients were followed up by weekly x-ray controls for the first month. Patients were assessed for unacceptable shortening and misalignment.

Results: Mean (SD) shortening during cast treatment was 2.9 (5.1) mm on the treated site. Shortening was detected in 16 patients (88.9%) in group 1 and in 7 patients (24.1%) in group 2. A significantly higher number (P < 0.001) of patients developed shortening in group 1. However, unacceptable shortening (>25 mm) did not develop in any patient in both groups. There was no significant frontal plane malalignment in both groups (P > 0.05). Sagittal plane malalignment was significantly higher in group 1 (P < 0.05).

Conclusions: Hip spica cast, which is incorporated to a distal femoral traction pin, avoids unacceptable shortening and frontal plane malalignment in pediatric femoral fractures, which even have a relatively high risk of unacceptable shortening based on the so-called telescope test. However, the technique cannot avoid sagittal malalignment.